#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<unistd.h>

int main()
{
    pid_t pid;
    printf("Before:pid is %d\n", getpid());
    if((pid = fork()) == -1) 
        perror("fork()"), exit(1);
    printf("After: pid is %d, fork return %d\n", getpid(), pid);
        sleep(1);
    return 0;
}

//int gval = 100;
//
//int main()
//{
//    printf("我是一个进程， pid: %d, ppid: %d\n", getpid(),getppid());
//    return 0;
//}
